UPDATE: FBI Lab Tests Negative on Suspicious Letter

UPDATE: Wednesday, 3:45 p.m. June 12, 2013.

No threatening substances were detected in or on the suspicious letter discovered at a Napa business yesterday, said Napa County Sheriff's Capt. Tracey Stuart.

"Lab test results were negative for all biological threats (including anthrax) from yesterday's suspicious letter discovered at The Doctors Co.," Stuart said today.

The tests were done at the labs used by the FBI office in San Francisco. The FBI confiscated the letter yesterday afternoon following evacuation of the business and decontamination of two employees who had touched the lette

ORIGINAL STORY: Tuesday, 4 p.m. June 11, 2013.
The San Francisco FBI has launched an investigation to determine who sent a letter with traces of suspected dried blood and a reference to anthrax to a Napa insurance company.

The letter, discovered at about 7 a.m. today in the mailroom of The Doctors Co., a medical malpractice insurance firm at 185 Greenwood Road in Napa, has been sent to an FBI lab for testing to determine if it did contain dried blood and/or traces of anthrax, said Napa County Sheriff's Capt. Tracey Stuart.

Stuart said the company contacted the Napa County Sheriff's Office to report the suspicious package after two employees opened the letter and found the suspected blood and reference to anthrax.

Sheriff's deputies responded, along with Cal Fire/Napa County Fire, Cal  Fire Hazardous Materials unit, and Napa County Public Health Officer Dr. Karen Smith. The building was evacuated and most of the employees went home, Stuart said.

The two employees who had contact with the letter were separated and tested and found not to have any contamination. They were also sent home, Stuart said.

Stuart said the firm's building was released back to company officers between 11 and 11:30 a.m. The FBI arrived and took possession of the letter at about 1 p.m., she said.